The waterway in the middle reaches of the Yangtze River has the characteristics of large hydrological variation,variable riverbed erosion and sedimentation,and complex river and lake relationships,making it difficult to determine the dredging timing.This paper reveals the factors affecting the dredging timing and establishes a method to determine the dredging timing.The results show that the main influencing factors of dredging timing include water level process,riverbed erosion and sedimentation,dredging capacity,and navigation status.At the same time,the values of parameters such as dredging design water level,maintenance water depth,reserved water depth,maximum underwater vertical depth of ship arm extension,dredging volume,dredging efficiency are given,and the method for determining dredging timing based on these parameters is determined.Taking the maintenance dredging of Taipingkou waterway in 2023 as an example,the water-level process from 2018 to 2022 is analyzed.The optimal dredging timing is from early September to the end of October in 2023.The research results can provide technical support for the dredging of similar waterways.